Use api with site with custom authorization

Hi, I want to use the api connector to retrieve data from Crex24. However, Crex doesnt use a standard authorization protocol, its custom and is based on methods not available in the authorization choices (like SHA512) .

The public ones work just fine:

but the ones requiring authorization require extra effort. I am confused as to how I might make these work with the API connector.

these are the calls I would like to do

but here is the code in order to be able to do them. How do I get this code executed in order to retrieve the data I want?

There is sample code at that last link